Dual Motor Drive System Based on Distributed Battery Pack Modular Multilevel Converter

The European Call HORIZON-CL5-2024-D5-01-02 suggested goals and future trends for electric powertrains. Focusing on the next-generation electric vehicles, 1.2 kV architectures were recognized to be suitable outcomes for improving the state of the art, enabling a strong reduction in the charging current and enlarging the vehicle driving ranges. Nevertheless, sizing all the vehicle components for such high voltage could be counterproductive. Hence, this work proposes the adoption of a 1.2 kV DC, 350 kW modular multilevel converter with distributed battery packs that can carry out ultra-fast-DC recharges. Its modular nature allows sizing the power electronics and several passive components on much lower voltage levels, with low cost-per-component and limited losses. In addition, this converter topology proved to be flexible, implements cell battery balancing algorithms and ensures backwards compatibility with the existing DC and AC charging modes without the need for any additional on-board charger. Finally, the converter can be installed on a dual motor powertrain. This paper shows an electric drive involving two 440 V, 75 kW induction machines. The traction and DC-charging capabilities of the converter were experimentally verified with a small-scale prototype.